Debug Probes - J-Link

JTAG/SWD debug probe with USB interface

SEGGER J-Links are the most widely used line of debug probes available today. They've proven their value for more than 10 years. This popularity stems from the unparalleled performance, extensive feature set, large number of supported CPUs, and compatibility with all popular development environments.

With up to 3 MBytes/s download speed to RAM and record breaking flashloaders, as well as the ability to set an unlimited number of breakpoints in flash memory of MCUs, the J-Link debug probes are undoubtedly the best choice to optimise your debugging and flash programming experience.

J-Link debug probes support ARM 7/9/11, Cortex, Microchip PIC32, Renesas RX CPUs as well as SPI flash devices. Here is the complete list of microcontrollers and SPI flash devices that are supported by J-Link.

The J-Link debug probes are supported by all major IDEs such as Keil MDK-ARM, GDB-based IDEs and SEGGER Embedded Studio.

J-Link Models

Working with J-Link

J-Link can be used for programming flash targets with the J-Flash software or stand-alone.

Setting up J-Link for first use

In order to use J-Link for the first time you need to install the J-Link related software and documentation pack which, among others, includes the J-Flash software and connect J-Link to the host PC via USB.

Connecting the target system

Power-on sequence

In general, J-Link should be powered on before connecting it with the target device. That means you should first connect J-Link with the host system via USB and then connect J-Link with the target device. Power-on the device after you connected J-Link to it. If you use J-Link PRO with Ethernet, just power-on J-Link via external power supply.

Verifying target device connection with J-Link.exe

If the USB driver is working properly and your J-Link is connected with the host system, you may connect J-Link to your target hardware. Then start the J-Link command line tool JLink.exe, which should now display the normal J-Link related information. Now type connect and specify your target and the target interface. Once done it should display a report about the connected CPU and its debug interface. The screenshot shows the output of JLink.exe. As can be seen, it reports a J-Link connected to an STM32F205 and the related information.

Start using J-Link with your favourite tool-chain

To connect your J-Link with your development project, please consult the guide for your favourite tool-chain.

Product Demonstration Videos

J-Link Model Overview

J-Link PRO is a refined version of the regular J-Link. It has an Ethernet interface in addition to the USB interface, as well as two additional LEDs which are used as hardware status indicators. It connects via Ethernet or USB to the host, running Windows, Linux or Mac OS X.

J-Link PLUS is a USB powered JTAG emulator supporting a large number of CPU cores. Based on a 32-bit RISC CPU, it can communicate at high speed with the supported target CPUs. J-Link is used around the world in tens of thousand places for development and production (flash programming) purposes.

J-Trace for Cortex-M is a JTAG emulator designed for Cortex-M cores which includes trace (ETM) support. J-Trace for Cortex-M can also be used as a J-Link and it also supports ARM7/9 cores. Tracing on ARM7/9 targets is not supported.

Main features

Has all the J-Link functionality

Hi-Speed-USB 2.0 interface

JTAG speed: 25 MHz Works with all currently available Cortex-M devices at 100 MHz trace clock

J-Trace PRO for Cortex-M is setting a new standard for trace probes. It enables continuous streaming trace via its Gigabit Ethernet interface, lifting the limitations by internal buffers and slow data transmission. J-Trace PRO can capture complete traces over long periods - thereby enabling the recording of infrequent, hard-to-reproduce bugs. This is particularly helpful when the program flow 'runs off the rails' and stops in a fault state.